Idaho Code § 30-30-607: Resignation of directors.

(1) A director may resign at any time by delivering written notice to the board of directors, its presiding officer or to the president or secretary.

(2) A resignation is effective when the notice is effective unless the notice specifies a future effective date. If a resignation is made effective at a future date, the board may fill the pending vacancy before the effective date if the board provides that the successor does not take office until the effective date.